Section 2 Digital Electronics

In order to assimilate the following mateial, the reader should be familiar with a few simple concepts in instrumentation elecronics. These topics are more than adequately discussed in numerous texts and so we do not belabor them here. For the convenience of those who need to review, we have prepared a list of subjects essential to understanding these introductory sections. This list is all-inclusive, so study of topics not on the list (e.g., ac circuit theory, inductance, transformers, power supplies, digital electronics, transducers, transistors, etc.) will be of no immediate value. 

Section 1 contains four chapters on basic electrical circuits, operational amplifiers, digital electronics and computers, signals, noise, and signal-to-noiso enhancement. 

Circuitry for impedance measurements has changed dramatically since the first measurements were performed on biological tissue. The development of digital electronics and the incorporation of computer power in almost all instruments have had an important impact on the possibilities of studying the passive electrical behavior of biomaterials over a wide frequency range, and with a speed that was not feasible only a few years ago. Only a brief summary of some of the techniques will be given in this section. 

Fig. 2.3 Top Cross-sectional scanning electron micrographs of the micromorphology of Pt ionic-polymer metal composites after treatment of the initial compositing process (ICP) (a) and the surface electroding process (SEP) (b). The bottom images show the cross-sectional view of the digital scanning microscope of the Pt IPMCs, where the treatment of ICP is again shown on the left and SEP on the right. Reprinted from [Park et al. (2008)] with permission from Cambridge University Press.

You should not use a mercury thermometer in direct contact with an aluminum block. If it breaks, the mercury will vaporize on the hot surface. Instead, use a nonmercury thermometer, a metal dial thermometer, or a digital electronic temperature-measuring device. See Technique 6, Section 6.1. 

In order to compare the wall thickness distribution results from both softwares with actual results, the entire bottle cross section wall thickness on vertical direction was measured. Figure 6 shows the comparison of actual measured sidewall thickness of the PET bottle and the simulation results of thickness distribution from B-SIM and BlowView. A digital electronic calliper was used for measurement on every 20mm cross section of 300mmarc length. 

Figure 11 Cross-sectional images of the specimen shown in Figure 10(a). The black parts indicate 0s04-stained butadiene domains. The electron beam is along the Z-axis. (a, b) Cross-sectional digitally sliced images at different depths of a 1-pm-thick sample. The depths of X-Kslices are indicated by dashed lines in (c). The electron beam was incident from the top and, hence, image (b) is obtained deeper inside the thick specimen. The detailed structures of the salami structure near the surface, that is, part (a), appear to be clearer than those inside the specimen, that is, part (b). Reproduced with permission from Macromolecules, 2010, 43,1675-1688. Copyright 2010 American Chemical Society.

We are all familiar with tire tliree states of matter gases, liquids and solids. In tire 19tli century the liquid crystal state was discovered [1 and 2] tliis can be considered as tire fourtli state of matter [3].The essential features and properties of liquid crystal phases and tlieir relation to molecular stmcture are discussed here. Liquid crystals are encountered in liquid crystal displays (LCDs) in digital watches and otlier electronic equipment. Such applications are also considered later in tliis section. Surfactants and lipids fonn various types of liquid crystal phase but this is discussed in section C2.3. This section focuses on low-molecular-weight liquid crystals, polymer liquid crystals being discussed in tire previous section. 

In this section, the conceptual framework of molecular orbital theory is developed. Applications are presented and problems are given and solved within qualitative and semi-empirical models of electronic structure. Ab Initio approaches to these same matters, whose solutions require the use of digital computers, are treated later in Section 6. Semi-empirical methods, most of which also require access to a computer, are treated in this section and in Appendix F. 

Each specimen was dehydrated, infiltrated and embedded in Technovit based methylmethacrylate. One section was cut and around in preparation for scanning electron microscopy (SEM). In each case, three overview photos were necessary and four high magnification fields (40X) were photographed and digitized. These fields were later analyzed for volume fraction of soft tissue, bone... 

Electronic devices such as automatic titrators and digital burets may be used in place of the traditional glass buret and manual titration. Such devices provide electronic control over the addition of titrant and thus, with proper calibration, are accurate, high-precision devices. These will be discussed in Section 4.9. 

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